Method of making elbows from sheet metal



Dec. 22,1925. 1,566,768

F. H. OTIS METHOD OF MAKING ELBOWS FROM SHEET METAL Filed March 20, 1924 FLE, v r I INVENTOR.

- I Frank J 0}[5 BY V 5% H15 4 TTORNEYS.

I Patented Dec. e2, .1925. p

UNITED STATES PATENT OFFICE FRANK H. OTIS, OF SKANEATELES, NEW YORK.

METHOD or MAKING ELBOWS rnom smear METAL;

Application filed March 20,

To all whom it may concern: 7 K I 7 7 Be it known thatl, FRANK H. O'rIs, a citizen of the United States, and resident of Skaneateles, in the county of Onondaga and State of New York, have invented certain new and useful Improvements in Methods of Making Elbows from Sheet Metal, of which the following is a specification.

The present invention relates to a method of making elbows from sheet metal and more particularly to the type in which the elbow has but a single seam and is free from ribs or corrugations for obtainingthe bend. An object of this invention is to provide an improved method which will make it possible.

to obtain the elbow from a minimum amount operation;

Fig. 2 is a section on the line 22, Fig. 1;

Fig. 3 is a plan view of the blank after it has been subjected to the second or trimming operation;

Fig. 4 is a side view of the blank after it has been subjected to the third or stamping operation v Fig. 5 is an end view after it has been subjected to the third operation;

Fig. 6 is a plan view after it has been sub- 7 jected to the fourth stamping operation;

Fig. 7 is a side view of the blank after it' has been subjected to the fourth operation; I Fig. 8 is an end view of the blank as pro duced by the fourth operation;

is subjected to a shaping operation prefer- Fig. 9 is a side view of the blank after it has been subjected to the fifth-or stamping operation; i

Fig. 10 is a section on the line 1010, Fig. 9;

Fig. 11 is a side view-of the completed elbow; V

Fig. 12 is 'a section Fig. 11; and

Fig. 13is an enlarged section through the on the line 12 1 2,

In carrying out this invention a flat piece of sheetmaterial preferably of circular form 1824. Serial No. 700,720.

ably by pressing in which a cup shaped portion 1 is produced surrounded by an annular j flange 2. The next operation consists in cutting the flange 2 of the blank produced in Fig. 1 to provide arms 3 which widen at their inner ends and merge into the perimeter of the cup shaped portion 1. The

nex operation consists in 'shapingthecup shajfii portion so that it becomes elongated orgnarrowed as at 4 on an axis transversely tof the blank shown in Fig. 3, and at the same time the arms 3 are bent at their inner ends so that they lie in parallel relation as shown atfi and in planes at right angles to the plane 770 of the elongated cup shaped portion 4.

The fourth operation illustrated in Figs 6, 7 and 8 consists in bending the parallel arms 5 of Figs. 4 and 5 to provide concave arms 6. The fifth operation consists in bending the arms inwardly oyer the elongatedcup shaped portion and, at thesame time, cure ing them so that a tubular elbow 7 is provided substantially oval in cross section as shown in Fig. 10, the adjacent. free edges of the armsbeing slightly separated. The sixth operation consists in seamingthe meeting edges of the blank together as shown at 8, Figs. 12 and 13, and, at the same'time, re-

shaping the tubular member so that it has a 35 substantially circular cross section showing the complete elbow as in Figs. 11 and 12.

From the foregoing'itwill be seen that there has been provided an improved method of forming elbows from sheet metal so that theelbow has a single seam and is free from transverse creases-or bends. It will be noted that the trimming or cutting operation occursafter the first pressing operation. This is desirable as this pressing operation 9 stretches the metal and will destroy the gen- .eral outline of the original blank, making it possible to provide a uniform blank in the first instance. It will also be noted that applicant obtains the elongated cup portion by 100 two operations, one a' cylindrical cup portion and thenthe final elongated cup portion.'

What I claim as my invention and desir'e I to secure by Letters Patent is: V

' 1. The method of forming sheet metal el- 10.5

bows which consists in shaping a flat sheet to provide a circular cupped portion and a flange beyond said cupped portion entirely surrounding said cupped portion, removin the flange except at two diametrically op- 11o posite portions to rovide two projections, the inner ends of w 10h widen and merge inmeeting edges may be interlocked.

.to the perimeter of the cupped portion, shapingthe cupped portion to narrow the same in a direction transversely of the length of the projections, and, at the same time, bending the projections and portions of the cupped portion-to rovide flattened portions extending in one irection at angles to the general plane'of the elongated cupped portion, concaving the outer faces of the flattened portions, and bending the concave portions toward each other so that their 2. A method of forming sheet metal elbows which consists in shaping a fiat piece to provide a circular cup portion and a,

flange beyond said cup portion, removing the flange except at two diametrically opposite.

portionsito provide two projections, and thereafter nai'rowing the cup portion in a direction transversely of the elbow and bending the projections to bring their edges into interlocking relation.

3. A method of forming sheetlmetal elbows lvhichigqnsists in shaping a flat sheet to provide a circularcupped portion, and a flange be 0nd said cupped portion, removing the ange except at two diametrically opposite portions to provide two projections,

shaping the cupped portion to narrow the same, in a direction transversely of the length of the elbow and, at the same time, bending the projections to cause them to extend in one direction at right angles to the plane ofthe-elongated cupped. portion, and thereafter curving and bending the projections to bring them into interlocking rela-' 4. A method of forming sheet metal e1- bows" which consists in shaping a flat sheet to provide a circular cupped portion and 'a flange beyond said cupped portion, re-

moving the flange except at two diametrically opposite portions to provide two pro-" jections, narrowing the cupped portion in a direction transversely ofthe len 'th of the elbow and, at the same time, ben ing without curving the rojections to cause them to extend parallel with each other and at right angles to the original plane of the sheet, concaving the outer faces of the projections to cause them to extend on r the cupped portion while, at the same time, providing the inner curve of the elbow and thereafter bending theprojections toward each other to provide the curved outer sides of the elbow.

FRANK H. o'rIs. 

